Smoke generator



March 6, 1962 B. G. SMITH SMOKE GENERATOR Filed Jan. 26, 1959 ,0 FIG E \11 1a fl 22 20 33 12 F I E l v INVENTOR.

Boas/z 31W TH Arrazzvrr United States Patent Iowa Filed Jan. 26, 1959, Ser. No. 789,178 1 Claim. (Cl. 252-359) This invention relates in general to a smoke generator, and in particular to an apparatus for quickly generating large quantities of smoke for wind tunnels and other purposes.

It is often desirable to generate smoke for use in aeronautical'studies, as for example in wind tunnels to study flow patterns, or in military applications where smoke is used to produce camouflage.

The present invention relates to a smoke generator which is capable of almost instantaneously producing smoke in s'utiiciently large quantities to allow good smoke patterns to be obtained in wind tunnels and other applications. I

Another object of this invention is to provide a relatively simple smoke generator which can be manufactured for a low cost.

A feature of this invention is found in the provision for a smoke generator which utilizes wicks supported by heating elements to generate large quantities of smoke.

Furtherlobjects, features, and advantages of this invention will become apparent from the following description and claim when read in view of the drawings, in which:

FIGURE 1 is a partial sectional view of the invention, and

FIGURE 2 is a top view of the invention.

A supporting member holds a bracket 11 that may be connected by screws or other suitable means. A glass or other suitable container 12 is connected to the bracket 11 by means of a connecting lid 13. An air inlet tube 14 extends through the lid 13. A filler neck 16 with a suitable cap 17 also extends through the lid 13. A second lid 18 is attached to the lower end of the pipe 14. The lower end of the filler neck 17 extends therethrough.

A second container 19 is attached to the lid 18. Wicks 21 extend through openings formed in the lid 18 and terminate below the top of the lid 13. Wicks 21 might be made of Fiberglas or other suitable material.

The air inlet pipe 14 does not extend through the lid 18, but has an opening 22 adjacent the wicks 21 so that air will be passed by the wicks. A suitable blower means 23 supplies air to the air inlet 14.

A transformer 24 is mounted on the bracket 11 and is connected by suitable leads 26 and 27 to a power supply, not shown. Leads 28 and 29 extend from the transformer to terminals 31 and 32 mounted on the lid 13. Terminals 31 and 32 are insulated from the lid 13.

Heating wire 33 is connected to terminal 31 and wound about the upper ends of the wicks 21. The end 34 returns to terminal 32, thus completing the electrical circuitry. A smoke outlet tube 36 extends into the plenum chamber formed by the container 12 and the lid 13 and supplies smoke to a smoke rake 37, for example.

In operation, cap 17 is removed and a smoke-generating liquid is supplied through the tiller neck 16 into the container 19. Various liquids are appropriate for this purpose, and for example Lifelike Smoke, a substance readily available on the market, might be used. The circuit is closed to the power supply through the leads 26 and 27, and the Nichrome wire 33 will heat up about the wicks 21. A voltage of 6.2 volts at two amperes might be supplied by the leads 28 and 29 to the heating elements 33. Such a voltage does not render the wire hot enough to make it glow, but does produce sufiicient heat to produce large quantities of smoke. The blower means 23 is energized, forcing air down the air inlet pipe 14 and out the opening 22, past wicks 21. The wicks contain a certain portion of the liquid smoke-generating substance from the container 19 and large quantities of smoke will pass out the smoke outlet 36 to the smoke rake 37.

It has been observed that a smoke generator according to this invention is capable of generating smoke within thirty seconds from the time it is turned on, and that the rate of producing smoke is uniform and in large quantities.

Although the invention has been described with respect to a preferred embodiment thereof, it is not to be so limited, as changes and modifications may be made therein which are within the full intended scope of the invention as defined by the appended claim.

What is claimed is:

An apparatus for generating smoke, comprising: a con tainer with smoke-generating liquid therein; a wick one end portion of which. is external of said container and the other portion of which extends into said container and is immersed in said liquid therein; a coil surrounding and engaging said one end portion of said wick for supporting said wick and providing heat thereto; electrical means for heating and supporting said coil; and means for blowing air past said coil and wick to produce large quantities of smoke.

References Cited in the file of this patent UNITED STATES PATENTS 1,727,899 Odlum Sept. 10, 1929 2,465,762 Supplee Mar. 29, 1949 2,850,615 Luse et a1 Sept. 2, 1958 2,882,640 Kopecky Apr. 21, 1959 2,899,722 Adams Aug. 18, 1959 FOREIGN PATENTS 151,202 Australia May 1, 1952 518,636 Canada Nov, 15, 1955 

